A method of fusing a component to a sterilized storage or delivery device formed of a cyclic olefin polymer which includes forming the storage or delivery device from a cyclic olefin polymer, forming a second member or component having at least a surface layer formed of the second polymer, wherein the Hansen relative energy distance Ra/Ro of the second polymer relative to the cyclic olefin polymer is equal to or less than 0.7, applying the second member to the storage or delivery device, and heating the assembly to the sterilization temperature, thereby causing the second polymer to chemically interact with the cyclic olefin polymer, fusing the second component to the storage or delivery device. The preferred embodiment of the invention is a medical container, such as a vial, wherein the vial is formed of a cyclic olefin polymer and the cap, closure or collar is formed of a second polymer heat fused to the vial or container.